Gas-detector.



No. 754,596. PATENTED MAR.'15, 1904. G. A. NELSON.

GAS DETECTOR.

APPLUATION FILED FEB.10. 1903.

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UNITED STATES Patented March 15, 1904.

PATENT OFFICE.

GAS-DETECTOR.

SPECIFICATION forming part of Letters Patent No. 754,596, dated March. 15, 1904i Application filed vFebruary I0, 1903. Serial No. 142,737 (No model.)

To @ZZ whom, t may concern:

Beit known that I, GEORGE ADoL'PH NEL- SON, acitiZen of the United States, residing at Providence, in the county of Providence and State of Rhode Island, have invented a new and useful Gas-Detector, of which the following is a speciication.

My invention relates to devices for detecting the presence of such substances as illuminating and like deleterious gases, more particularly in rooms and living apartments, and for actuating an alarm to warn the occupants or others of the presence or' said gas.

The object is to provide a sensitive and certain means for effecting this purpose.

The accompanying drawing shows a perspective and diagrammatic view oil one lembodiment of my invention.

The character O designates a suitable cage or casing, here shown as consisting' of top and bottom plates lO 1l, respectively, conveniently of some such material as wood, separated the proper distance by connectingrods I2 or the like. Upon the top plate a hook 13 may be provided for suspending the casing in its operative position. Vithin the casing is disposed an unconnected movable body, preferably a balloon I4, formed of some such thin light envelop as rubber lined with oiled silk, or oiled silk alone may be used, if desired, which will retain a charge of the gas the `presence of which is to be detected, or Some similar gaseous fluid having approximately the same specific gravity thereas, but which must be diierent from air. rlhis balloon will normally assume a position at the top of the casing, as is shown in full lines in the drawing. To the lower portion of this balloon is attached, conveniently by light-cords or threads I5, a metallic member or circuit-changing device 16, it in the present instance acting' as a circuit-closer.

Upon the upper surface of the plate l2 are mounted two contact members 17 17, which are spaced apar't and located beneath the member 16, and from these lead wires 18 18 of an`electrical circuit, here shown as normally open, containing some suitable alarm device, as a bell 19,' which maybe placed in the room with the detector or at some central point of a system, as in the oihce of a hotel.

In use my device is attached at the ceiling of an apartment, and the balloon, being iilled with a gas lighter than air, will rest against the top plate of the casing. If gas enters the room through a leak in the fixtures or otherwise, it will rise to the ceiling. Now, as the balloon as a whole must be heavier than its gaseous contents, as it becomes surrounded by the gas it will gradually fall, and when a suicient amount of said gas has entered it will assume the position indicated by dotted lines in the drawing, with the member 16 resting upon the contact members 17. This will close the electrical circuit and actuate the-alarm, giving' a warning of the presence of free gas in the room.

It will be seen that many changes may be made in the arrangement of the alarm-cin,

cuits and other details of construction withoutl departing from the spirit oi' my invention.

Having thus described my invention, I claiml. The combination with an alarm, of a float maintained in suspension wholly by the atmosphere, said float being freely movable and adapted to descend upon the displacement of the atmosphere by a lighter fluid, and means controlled by the descent oi' the loat for actuating the alarm.

2. The combination with a support, of a pair of spaced contacts carried thereby, an alarm in open circuit with the contacts, afioat disposed directly above the contacts and mainsion Wholly by the atmosphere, said oat be- In testimony that I claim the foregoing as ing freely movable and adapted to descend my ownlhiwe hereto allxed my Signnturein upon the dlsplzteement or the atmosphere by the presence or two Wltnesses.

:t lighter Huid, and a member Carried by the GEORGE ADOLPH NELSON. 5 float and adapted upon the descent of the lVitnesses:

latter to cooperate with the contacts for olos- PATRICK J. B/ICELROY. [L S.]

ing' the circuit to aetnztte the alarm. ABRAHAM KoZLoW. [n s@ 

